Question

In the figure below, the m∠2 is 50°. Find the m∠1. Label your answer.

Answer 1

Note that m∠4 and m∠1 are vertical angles, and so they would have the same measurements (same for m∠3 & m∠2). Note that m∠1 and m∠2 are supplementary angles (going to have a total measurement of 180°)

m∠2 = 50° (given)

m∠1 + m∠2 = 180

m∠1 + 50 = 180

Isolate m∠1. Note the equal sign. What you do to one side you do to the other. Subtract 50 from both sides

m∠1 + 50 (-50) = 180 (-50)

m∠1 = 180 - 50

m∠1 = 130°

m∠1 = 130° is your answer

hope this helps